Protective shield assembly for space optics and associated methods

ABSTRACT

A protective shield assembly capable of being deployed from a launch vehicle is provided, and methods for assembling and deploying the protective shield assembly are also provided. The protective shield assembly includes a shroud, and a flexible sheet of material within the shroud. The flexible sheet of material is capable of substantially conforming to a contour of at least a portion of the launch vehicle to provide a protective barrier.

BACKGROUND OF THE INVENTION

1) Field of the Invention

The present invention relates to a shield for space optics and, moreparticularly, to a shield for protecting space optics from heat andcontamination.

2) Description of Related Art

Interceptors, such as missiles or rockets for air defense, use varioustechniques for in-flight guidance in order to identify and/or engageairborne objects. If the interceptor is searching for a ballisticmissile, the interceptor must not only be capable of tracking themissile but also distinguishing between the missile and any decoys.Examples of in-flight guidance techniques include devices, technologies,and media using infrared or visible cameras or detectors, LADAR,transducers, or other sensors, including sensitive components such aslenses, mirrors, lasers, or fiber optics, to transmit or detect light,other electromagnetic energy such as millimeter waves, or other forms ofenergy, such as sound waves.

Interceptors that employ optical systems for targeting include opticsand electronics that are susceptible to overheating and contamination.In particular, during launch and at high speeds, the interceptor issubjected to frictional heating from air passing at high speeds over theinterceptor causing increased temperatures that re-radiate to theoptical surfaces and electronic assemblies. In addition, vibrationcaused during launch and flight frees particulate contamination from theinterior of the interceptor that may re-deposit on the optical surfaces.As a result of the heat and contamination, the optical system willprovide a lower signal-to-noise ratio due to obscuration fromcontaminants, increased infrared background from contamination andheating, and blurring due to warping of the optics from heating.

Different techniques have been developed to protect the optical systemwhile airborne. One technique is to use a cover or group of covers thatare positioned proximate to the nose of the interceptor and over theoptical system while the interceptor is airborne. The cover(s) are laterpivoted, ejected, or otherwise moved with mechanical devices to allowthe optical system to operate. However, this system cannot provideprotection from heat and contamination proximate to the cover itself andits deployment.

Another technique for protecting the optical system is a shroud that isdisclosed in conjunction with an aircraft, where the shroud typicallyconforms to the nose of the aircraft and may later be deployed and,therefore, removed once the aircraft reaches a designated speed. U.S.Pat. No. 4,850,275 to Utreja et al. discloses a shroud positioned foreof a hollow nose portion that may be removed once the aircraft reaches adesignated speed. The nose portion includes an optical window positionedaft of the shroud such that when the shroud is removed, the opticalwindow is revealed. The shroud is designed to be detached automaticallyfrom the nose portion once the airplane obtains a desired altitudeand/or speed. Within the nose portion, a nose cavity includes a baseannularly surrounded by a rim. The optical window is integral to thebase of the nose cavity, where the base is formed deep within the cavityto minimize convective heat flow along the base portion and conductiveheat flow along the rim and cavity walls. The cavity of the nose portionis configured to lower the heat transfer coefficient and the unsteadydensity fluctuations about the optical window. However, there is noprotective shield between the shroud and the optical window such thatthe optical window is still susceptible to heat radiation andcontamination traveling from the interior of the shroud and through thenose cavity, which increases the probability for blurring of the opticalsystem. In other words, while the shroud protects the optical window andthe optical system that communicates through the optical window fromexternal communication, the optical window is not protected fromcontamination originating from the shroud itself.

It would therefore be advantageous to provide a protective shield thatis capable of protecting systems disposed within a launch vehicle, suchas from heat and contaminants. It would also be advantageous to providea protective shield that is capable of being deployed from the launchvehicle with a shroud. It would further be advantageous to provide aprotective shield that is inexpensive and easily removed when deployed.

BRIEF SUMMARY OF THE INVENTION

The invention addresses the above needs and achieves other advantages byproviding a protective shield assembly that is capable of protectinglaunch vehicle components, such as an optical system, and thereafterfurther capable of being deployed and, therefore, removed from a launchvehicle, such as a missile. The protective shield assembly includes ashroud and a flexible sheet of material within the shroud that iscapable of conforming to the contour of a portion of the launch vehiclethat may be susceptible to heat and contaminants. Thus, while the shroudprotects the launch vehicle components from external contaminants, theflexible sheet of material protects the launch vehicle components fromcontaminants originating within the shroud and launch vehicle, as wellas heat. When the shroud is deployed, the flexible sheet of material isalso advantageously pulled away from the launch vehicle to expose aportion of the launch vehicle, which is typically an optical system,thereby exposing the optical system for operation.

In one embodiment of the present invention, a protective shield assemblycapable of being deployed from a launch vehicle is provided. Theprotective shield assembly includes a shroud, and a flexible sheet ofmaterial within the shroud. In one embodiment, the flexible sheet ofmaterial may be a thermally insulating material, which could be amultilayer insulation material such as a polyester film. The polyesterfilm may include a reflective metallic coating such as gold or aluminum.As such, the flexible sheet of material may provide a thermal barrier.The flexible sheet of material is capable of substantially conforming toa contour of at least a portion of the launch vehicle to provide aprotective barrier. In one embodiment of the present invention, theflexible sheet of material attaches circumferentially to the shroud todefine a pocket between the shroud and the flexible sheet of material.In addition, the shroud may include a plurality of segments, and theflexible sheet of material may include a plurality of sheets ofmaterial, where each sheet of material may attach to a respectivesegment.

In addition, the present invention provides a system for deploying aprotective shield assembly from a launch vehicle. The system includes alaunch vehicle and a protective shield assembly attached to the launchvehicle, where the protective shield assembly was described above. Invarious embodiments of the system, the launch vehicle is a missileincluding an optical system disposed within the missile, and theflexible sheet of material typically conforms to a contour of theoptical system and is capable of providing a protective barrier for theoptical system from heat and contaminants. In addition, the flexiblesheet of material may define at least one fold between the shroud andthe optical system, where the fold is capable of substantiallyconforming circumferentially about the optical system.

A further protective shield assembly is provided in accordance with thepresent invention, where the protective shield assembly is capable ofbeing attached to a shroud. The protective shield assembly includes aflexible sheet of material having a covering portion, at least onefolding portion, and an attachment portion. The protective shieldassembly also includes a tie, such as a ring positioned about thecircumference of the shroud or rivets, that is capable of attaching theattachment portion to the shroud.

The present invention also provides a method for assembling a protectiveshield assembly on a launch vehicle. The method includes providing ashroud having a flexible sheet of material therewithin, such as by beingattached to the shroud. In various aspects of the method, the methodincludes attaching the flexible sheet of material circumferentially tothe shroud to define a pocket between the shroud and the flexible sheetof material. The method also includes connecting the shroud to a firstend of the launch vehicle such that the flexible sheet of materialsubstantially conforms to a contour of at least a portion of the launchvehicle, such as an optical system, to provide a protective barrier,such as from heat and contaminants. In connecting the shroud to a firstend of the launch vehicle, the flexible sheet of material may define atleast one fold between the shroud and the optical system, where the foldis capable of substantially conforming circumferentially about theoptical system.

The present invention provides an additional method for deploying aprotective shield assembly from a launch vehicle. The method includesproviding a launch vehicle having a shroud with a flexible sheet ofmaterial therewithin such that the flexible sheet of materialsubstantially conforms to a contour of at least a portion of the launchvehicle to provide a protective barrier. The method further includesdeploying the shroud from the launch vehicle such that the flexiblesheet of material is removed from the launch vehicle. For example, theshroud may be deployed from the launch vehicle to remove the flexiblesheet of material such that an optical system disposed within the launchvehicle is exposed. In addition, the method may also include igniting anexplosive device to release the shroud and the flexible sheet ofmaterial from the launch vehicle.

The present invention therefore provides many advantages. The flexiblesheet of material provides a protective layer that may conform about anoptical system disposed within a launch vehicle, such as a missile.Providing a flexible sheet of material enables the material to beconfigured about a variety of launch vehicle components to provide abarrier against heat and contaminants that may otherwise sacrifice theaccuracy of the components, such as an optical system. Thus, theincidence of a lower signal-to-noise ratio and blurring due to warpedoptics may be significantly reduced.

Furthermore, the flexible sheet of material may be an inexpensivematerial, such as a polyester film, and may be readily attached to theinterior surface of the shroud. Upon deployment of the shroud, theflexible sheet of material is also removed from the launch vehicle,which provides additional protection for the launch vehicle componentswithout affecting the ability of shroud to be deployed from the launchvehicle. Finally, because the flexible sheet of material has a broadarea of attachment substantially about the circumference of the shroud,the risk of failure during deployment is greatly reduced when comparedwith mechanical devices having a single or very few areas of attachmentand/or including techniques that have a higher risk of failure duringdeployment of the shroud.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Having thus described the invention in general terms, reference will nowbe made to the accompanying drawings, which are not necessarily drawn toscale, and wherein:

FIG. 1 is a cross-sectional view of a protective shield assemblyaccording to one embodiment of the present invention.

FIG. 2A is a partial cross-sectional view of a protective shieldpositioned on a launch vehicle according to one embodiment of thepresent invention;

FIG. 2B is a partial cross-sectional view of the protective shield shownin FIG. 2A in a partially deployed position according to one embodimentof the present invention;

FIG. 2C is a partial cross-sectional view of the protective shield shownin FIG. 2A in a deployed position according to one embodiment of thepresent invention;

FIG. 3 is plan view illustrating a missile employing a protective shieldaccording to one embodiment of the present invention;

FIG. 4A is a partial cross-sectional view of a protective shieldassembly illustrating a tie according to one embodiment of the presentinvention.

FIG. 4B is a partial cross-sectional view of a protective shieldassembly illustrating a tie according to another embodiment of thepresent invention;

FIG. 4C is a partial cross-sectional view of a protective shieldassembly illustrating a tie according to yet another embodiment of thepresent invention; and

FIG. 5 is a partial perspective view of a protective shield positionedon a launch vehicle illustrating a segmented shroud and respectiveflexible sheets of material according to one embodiment of the presentinvention

DETAILED DESCRIPTION OF THE INVENTION

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which some, but not allembodiments of the invention are shown. Indeed, this invention may beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will satisfy applicable legalrequirements. Like numbers refer to like elements throughout.

Referring now to the drawings and, in particular to FIG. 1 there isshown a protective shield assembly 10. The protective shield assembly 10generally includes a shroud 12 and a flexible sheet of material 14attached to an interior surface of the shroud. In general, theprotective shield assembly 10 is employed to protect launch vehiclecomponents, such as an optical system, that are disposed within thelaunch vehicle but later exposed when the assembly is deployed andremoved from the launch vehicle. However, it is understood that theprotective shield assembly 10 may remain attached to a launch vehicledespite having the capability to be deployed from the launch vehicle,such as in instances where additional protection is required foraccurate operation of the launch vehicle components.

As used herein, the term “launch vehicle” is not meant to be limiting,as the protective shield assembly 10 may be employed with any launchvehicle. For example, the launch vehicle could be any type of missile,having an interceptor or payload, an aircraft, a satellite, or otherairborne vehicle having sensitive components contained therein.

Furthermore, as used herein, the term “shroud” is not meant to belimiting and is known to those skilled in the art to include aprotective covering that is typically attached to a leading end of amissile. The shroud, also known as a fairing, could be employed with amissile or rocket, such as an interceptor, or a ballistic missile havinga payload, or any number of types of launch vehicles, as describedabove. The shroud is typically configured as a nose cone to reduce airresistance and drag during take off and while airborne. The shroud alsoprotects various launch vehicle components, where the components couldbe a guidance system, satellite, optical system, or payload, fromexternal aerodynamic loads, vibration, noise, temperature extremes,contaminants, and other environments that may be encountered as thevehicle is launched and accelerates through the atmosphere. The shroudalso serves as a protective shield for the launch vehicle componentswhile the launch vehicle is in storage. The shroud is typically deployedand removed or expelled from the launch vehicle once the launch vehiclereaches a predetermined speed or location. The shroud could be any sizeand configuration for various types of launch vehicles, and the shroudmay be, for example, a metallic or composite material, such as aluminum,graphite-epoxy, or wood.

The flexible sheet of material 14 is a semi-flexible material that isattached to an inner surface of the shroud 12 to define a pocket 15between the shroud and the sheet of material. Thus, any contaminantsthat have adhered to the inner surface of the shroud 12 that could comeloose will be captured or retained within the pocket 15. When theprotective shield assembly 10 is deployed from a launch vehicle, boththe shroud 12 and the sheet of material 14 will be disengaged such thatthe contaminants within the pocket 15 will be removed. The sheet ofmaterial 14 is typically a thin sheet attached near the base of theshroud 12 about the entire circumference of the shroud to define thepocket 15, although the sheet of material could be substantiallyattached at various points about the circumference of the shroud. Inaddition, it is understood that the sheet of material 14 may be attachedat various positions within the shroud 12 in further embodiments of thepresent invention to accommodate various launch vehicle components. Forinstance, the sheet of material 14 could be attached proximate to thebase of the shroud 12 adjacent to the launch vehicle, or the sheet ofmaterial could be attached further towards the nose of the shroud.

The flexible sheet of material 14 could be attached with a tie 16 aboutthe circumference of the shroud 12. FIG. 4A illustrates a tie 16positioned adjacent to, and circumferentially about, the shroud 12,where an attachment portion of the sheet of material 14 extends betweenthe tie and the shroud such that the tie secures the sheet of materialagainst the shroud. Thus, the tie 16 in this particular embodiment, maybe, for example, a snap ring or similar device that applies an outwardforce circumferentially about the shroud 12 that secures or pinches anattachment portion of the sheet of material 14 in position. Furthermore,the tie 16 could include a ring 24 attached to the inner surface of theshroud 12, where a plurality of clips 26 engage the ring, and anattachment portion of the sheet of material 14 includes a series ofgrommets 26 or eyelets that engage a respective ring, such as that shownin FIG. 4B. In addition, FIG. 4C demonstrates that the tie 16 couldinclude a bracket 30 attached to an inner surface of the shroud 12, anda plurality of rivets 32 may be inserted through an attachment portionthe sheet of material 14 and into the bracket about a circumference ofthe shroud. Similarly, rivets 32 could be inserted through the sheet ofmaterial 14 and directly into the shroud 12 such that the bracket is notrequired. The attachment portion of the sheet of material 14 istypically located proximate to a perimeter of the sheet of material,although the attachment portion could be positioned anywhere on thesheet of material and still be capable of attaching to the shroud 12.

The attachment technique used facilitates the sheet of material 14 beingejected with the shroud 12 such that the sheet of material is removedwhen the shroud is deployed from a launch vehicle. As such, the sheet ofmaterial 14 may be removed as a single unit with the shroud 12 as theentire protective shield assembly 10 is deployed from a launch vehicle.Moreover, attaching the sheet of material 14 substantially about thecircumference of the shroud 12 provides a lower risk of failure whenremoving the sheet, as several locations are required to fail before thesheet of flexible material detaches from the shroud and is no longerremoved with the shroud. Although the sheet of material 14 is shownattached to the shroud 12, it is understood that the flexible sheet ofmaterial could be integral with the shroud such that no attachmenttechniques are required.

The flexible sheet of material 14 is typically a lightweight andthermally insulating material, such as multilayer insulation (MLI)material that is capable of insulating and protecting an optical system18 from heat and contaminants. In one embodiment of the presentinvention, the sheet of material 14 includes a smooth cleanable surface,where the clean smooth surface faces, and may contact, the opticalsystem 18 to prevent any contaminants from depositing on the opticalsystem. The sheet of material 14 could also be a non-shedding orlow-outgassing material (i.e., a cleanroom material). The sheet ofmaterial 14 includes materials that are pliable and capable of beingshaped and conformed in a variety of configurations. For example, asshown in FIG. 2A, the sheet of material 14 includes a covering portionthat is configured to substantially conform to the size and shape of theoptical system 18. Being able to closely conform to the shape of theoptical system enables the sheet of material 14 to protect the opticalsystem 18 from contaminants that may break loose from the shroud 12 orlaunch vehicle by vibrations during flight or during storage andredeposit on the optical system. Thus, the covering portion of the sheetof material 14 is capable of providing a shield and/or conforming to avariety of launch vehicle components in various embodiments of thepresent invention.

Examples of MLI materials suitable for the flexible sheet of material 14in accordance with the present invention are polyester or Mylar® (E.I.Du Pont de Nemours and Company Corporation) films that preferablyinclude a thin reflective coating such as aluminum or gold. Otheracceptable MLI materials that are clean and electro-static safe arethose manufactured by Sheldahl Corp. (Northfield, Minn.) and SwalesAerospace (Beltsville, Md.). The coating is used to reflect infraredradiation to protect the optics from heat that may adversely affect thesensitive optical and electronic components within the launch vehicle.In one embodiment, the sheet of material 14 is 0.001 inches inthickness, although the sheet of material could be various thicknessesin alternative embodiments.

As depicted in FIG. 2A, the flexible sheet of material 14 may includeone or more folding portions or pleats 20. A portion of the sheet ofmaterial 14 extends longitudinally along and circumferentially about theoptical system 18, or at least the forward most portion of the opticalsystem, and forms at least one fold between the optical system and theshroud 12. In this configuration, the pocket 15 and folding portions 20prevent contaminants from migrating from the interior of the shroud 12,as shown by arrow 21 a in FIG. 2A, and the launch vehicle, as shown byarrow 21 b, and then redepositing on the optical system. Particularly,the folding portions 20 extend substantially along the longitudinal axisof the optical system 18 to prevent contaminants originating from thelaunch vehicle from contacting the optical system or even contacting thesheet of material 14 within the pocket 15 adjacent to the opticalsystem. Moreover, the folding portions 40 may trap hot expanding air andthermal radiation between the shroud 12 and the sheet of material 14,which protects the optical system 18 from excessive heat. Although thesheet of material 14 is shown having two folds, it is understood thatthere may be any number and configuration of folds in additionalembodiments of the present invention.

In an additional embodiment of the present invention, FIG. 5 depicts ashroud having a plurality of segments 12 a-b. Thus, the shroud segments12 a-b may be arranged to cooperatively form the shroud, which could be,for example, arranged in a nose cone configuration. The shroud segments12 a-b could be attached to a launch vehicle with bolts, pivots,mechanical latches, or similar devices, as well as other mechanismsknown to those skilled in the art. The shroud segments 12 a-b could beindependent of one another or attached, or otherwise, linked to oneanother. A plurality of flexible sheets of material 14 a-b attach to arespective shroud segment 12 a-b. As such, the sheets of material 14 a-bmay be arranged to at least substantially cover and shield launchvehicle components, such as an optical system 18. The sheets of material14 a-b could be independent of one another, such that the sheets are notattached to one another, or one or more sheets could be attached and,for example, peel away from one another when the segments are deployed.Generally, each sheet of material 14 is attached to the shroud segments12 a-b with a tie 16, such as, for example, rivets that extend through asheet of material and into a segment.

The shroud segments 12 a-b may be pulled away from the launch vehiclesequentially in designated time increments or simultaneously to exposethe optical system 18, or any other launch vehicle component, forobservation, communication, or subsequent deployment. As the shroudsegments 12 a-b are pulled away from one another, each segment acts topull away a respective sheet of material 14 a-b. Moreover, one or all ofthe shroud segments 12 a-b and sheets of material 14 a-b may be deployedand removed from a launch vehicle.

In the illustrated embodiment, there are two shroud segments 12 a-b andtwo sheets of material 14 a-b, however, it is understood that there maybe any number of segments and sheets, as well as additionalconfigurations, in further embodiments of the present invention. Forinstance, there could be five shroud segments 12 a-b and respectivesheets of material 14 a-b, there could be a single sheet of material 14that attaches to a plurality of shroud segments, there could a pluralityof sheets of material attached to a single shroud having no segments, orthere could be an odd number of shroud segments and sheets of material(e.g., three shroud segments and two sheets of material).

FIG. 3 illustrates the protective shield assembly 10 attached to amissile 22. The missile 22 could be an interceptor or a ballisticmissile, as known to those skilled in the art, or any type of rocketcapable of utilizing the protective shield assembly 10. Generally, theshroud 12 is removably and circumferentially attached to the missile 22.The technique used to attach the shroud 12 to the missile 22 preferablyallows for deployment and removal of the protective shield assembly 10from the missile at a predetermined time or speed while the missile isairborne. For example, the shroud 12 could be attached to the missile 22by bolts, mechanical latches, or similar devices, or other devices knownto those skilled in the art that may be released, for instance, byelectromechanical or explosive mechanisms.

The missile 22 shown in FIG. 3 includes an optical system 18, and in oneembodiment of the present invention, the optical system includes aninfrared camera. Although the protective shield assembly 10 is discussedherein in conjunction with an optical system 18, it is understood thatthe protective shield assembly could be utilized to protect any numberof launch vehicle components. For instance, the protective shieldassembly 10 could be used to protect a payload, guidance system, missioncomputer/microprocessor, power supply, or other electrical componentslocated in the fore portion of the missile 22, where the accuracy ofsuch components are susceptible to heat, contaminants, and otherenvironmental conditions. Furthermore, it is understood that the launchvehicle may employ any number of optional components, such as a fueltank, GPS antennas, low band and high band antennas, a flighttermination system, beacon, and telemetry, as known to those skilled inthe art.

FIGS. 2A-2C demonstrate the progressive stages of deployment of theprotective shield assembly 10 from a launch vehicle. FIG. 2A illustratesthe protective shield assembly 10 as it would appear when attached to alaunch vehicle, where the flexible sheet of material 14 is substantiallyconformed about the optical system 18, as also shown in FIG. 3. As theprotective shield assembly 10 is initially deployed, as shown in FIG.2B, the movement of the shroud 12 away from the optical system 18 alsocauses the flexible sheet of material 14 to pull away from the opticalsystem. When the shroud 12 is completely deployed from the launchvehicle, as depicted in FIG. 2C, the flexible sheet of material 14 ispulled away from the optical system 18 such that the optical system isexposed and fully functional.

The protective shield assembly 10 may be deployed from the launchvehicle using any technique known to those skilled in the art. Althoughvarious mechanical techniques may be employed with the presentinvention, explosives are preferably used to detach the protectiveshield assembly 10 from the launch vehicle, as there is a lower risk offailure when non-mechanical techniques are utilized. The explosivescould be positioned proximate to the attachment of the shroud 12 to thelaunch vehicle and detonated under the command of a microprocessorwithin the launch vehicle or from a remotely communicated signal.

Embodiments of the present invention provide many advantages. Theflexible sheet of material 14 provides a protective layer that mayconform about an optical system disposed within a launch vehicle.Providing a flexible sheet of material enables the material to beconfigured about a variety of launch vehicle components to provide abarrier against heat and contaminants that may otherwise sacrifice theaccuracy of the components, such as an optical system. Thus, theincidence of a lower signal-to-noise ratio and blurring due to warpedoptics may be significantly reduced.

Furthermore, the flexible sheet of material 14 may be an inexpensivematerial, such as polyester, and may be readily attached to the interiorsurface of the shroud 12. Upon deployment of the shroud 12, the flexiblesheet of material 14 is also removed from the launch vehicle, whichprovides additional protection for the launch vehicle components withoutaffecting the ability of shroud to be deployed from the launch vehicle.Finally, because the flexible sheet of material 14 has a broad area ofattachment substantially about the circumference of the shroud 12, therisk of failure during deployment is greatly reduced when compared withmechanical devices having a single or very few areas of attachmentand/or including techniques that have a higher risk of failure duringdeployment of the shroud.

Many modifications and other embodiments of the invention set forthherein will come to mind to one skilled in the art to which thisinvention pertains having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the invention is not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

1. A protective shield assembly for a launch vehicle comprising: ashroud; and a flexible sheet of material attached to the shroud so as todefine a pocket between the flexible sheet and the shroud, wherein atleast a portion of the flexible sheet of material is attached to theshroud so as to be capable of conforming to a contour of a surface to beprotected independently of the shroud.
 2. The protective shield assemblyaccording to claim 1, wherein the flexible sheet of material comprises athermally insulating material.
 3. The protective shield assemblyaccording to claim 2, wherein the flexible sheet of material comprises amultilayer insulation material.
 4. The protective shield assemblyaccording to claim 3, wherein the multilayer insulation materialcomprises a polyester film.
 5. The protective shield assembly accordingto claim 4, wherein the polyester film includes a reflective metalliccoating comprising one of gold and aluminum.
 6. The protective shieldassembly according to claim 1, wherein the flexible sheet of materialattaches circumferentially to the shroud to define the pocket betweenthe shroud and the flexible sheet of material.
 7. The protective shieldassembly according to claim 1, wherein the shroud comprises a pluralityof segments.
 8. The protective shield assembly according to claim 7,wherein the flexible sheet of material comprises a plurality of sheetsof material, and wherein each sheet of material attaches to a respectivesegment.
 9. The protective shield assembly according to claim 1, whereinthe flexible sheet of material comprises at least one fold definedbetween free ends thereof.
 10. The protective shield assembly accordingto claim 1, wherein at least one of the flexible sheet of material orthe shroud is configured to be removably attached to the surface to beprotected.
 11. The protective shield assembly according to claim 1,wherein the pocket between the flexible sheet and shroud is definedsubstantially along a length of the flexible sheet.
 12. A protectiveshield assembly for a launch vehicle comprising: a shroud comprising aplurality of segments; and a flexible sheet of material within theshroud, wherein the flexible sheet of material is capable ofsubstantially conforming to a contour of a surface to be protectedindependently of the shroud, wherein the flexible sheet of materialcomprises a plurality of sheets of material, and wherein each sheet ofmaterial is independently attached to a respective segment of the shroudand at least one of the plurality of sheets is configured to at leastpartially overlap another sheet of material.